Leydig-Cell Function in Children after Direct Testicular Irradiation for Acute Lymphoblastic Leukemia

Abstract

To assess the effect of testicular irradiation on testicular endocrine function, we studied 12 boys with acute lymphoblastic leukemia who had been treated with direct testicular irradiation 10 months to 8 1/2 years earlier. Insufficient Leydig-cell function, manifested by a low response of plasma testosterone to chorionic gonadotropin or an increased basal level of plasma luteinizing hormone (or both), was observed in 10 patients, 7 of whom were pubertal. Two of these patients had a compensated testicular endocrine insufficiency with only high plasma concentrations of luteinizing hormone. Testosterone secretion was severely impaired in three pubertal boys studied more than four years after testicular irradiation. A diminished testicular volume indicating tubular atrophy was found in all pubertal patients, including three who had not received cyclophosphamide or cytarabine. These data indicate that testosterone insufficiency is a frequent complication of testicular irradiation, although some patients continue to have Leydig-cell activity for several years after therapy.

Effect of Radiation on the Human Reproductive System

“…Ten of12 boys showed evidence of Leydig cell dysfunction 10 months-8.5 years after testicular irradiation (24 Gy in 12 fractions over 18 days) for acute lymphoblastic leukemia, indicated by a low testosterone response to an acute bolus of human chorionic gonadotropin (hCG) or an increased basal plasma LH level, or both (37). Similar findings were reported by Leiper et al (38).…”

Growth and endocrine function after bone marrow transplantation

“…The vulnerability of the Leydig cell to radiation damage is known to be age-dependent ) and a high incidence of severe Leydig cell damage has been observed after testicular irradiation in childhood when the irradiation dose exceeds 20 Gy (Brauner et al, 1983;Leiper et al, 1983;Shalet et al, 1985). Castillo et al (1990) demonstrated normal testosterone responses to hCG in prepubertal boys who received 12-15Gy to the testes in a fractionated schedule.…”

Hypogonadism After Childhood Cancer Treatment

“…However, this test is difficult to implement as it lasts for several days. Anyway, Brauner (1983) found good correlation between GnRH-test and HCG-test in males if performed in postpubertal period. Actually, our subjects were tested in postpubertal period.…”

“…Two of these patients had testicular RT (1200 cGy in 4 fractions). Other authors did neither observe clinically significant impairment of LC after the testicular dose of this size (Brauner et al 1983, Castillo et al 1999 (Pennisi et al 1975). All our 16 patients with LC damage had damage of germinal epithelium as well.…”

“…In the published articles studying gonadal function after childhood cancer treatment different multivariate analysis for analyzing risk factors were used, mainly logistic regression (Brauner et al 1983). However, this test is difficult to implement as it lasts for several days.…”